Transmission gearing



March 15,1927. 1

C. E. F. AHLM TRANSMISSION GEARING Filed Dec.

1924 s Sheets-She ei 1 I NvENToR 641w aw M ATTORN E'YS March 15,1927. 1,620,856 c. E F. AHLM TRANSMISSION GEARING Filed Dec. 1924 3 Sheets-Sheet 2 March 15,1927. 1,620,856

* c. E. F. AHLM Y TRANSMISSION GEARING Filed Dec. 1924 3 Sheets-Sheet 5 AT TO FT IQE YS mo Mu.15, 192 7.

PUNl S S cHAnLEsn. r. AHLM, or CLEVELAND, 0x10, AssIeNoB -'ro AUTOMOTIVE PATENT HOLDING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF DELAWARE.

I raausmrsslon GEABING.

This invention relates .to transmission gearing such for example as are used to connect driving and driven members, as the engine shaft and the rear axle or' propeller shaft of an automobile to secure a plurality of speeds and a reverse drive between'these members.

The general object of this invention is to provide a simple. and compact form of changing speed gearing mechanism employing an eccentrically mounted composite gear which may be easily and cheaply manufactured and assembled, the parts of which are of light 'weight, while being capable of transmitting a'great amount of power. A

further object is to arrange'a gearing of this character so that the relatively rotating parts may be very simply connected together as a unit when direct drive is desired.

' propeller member.

Another object may be stated to include the provision of an eccentric bearing for a composite internal-external gear which may be very easily assembled with a drive 'shaft and pinionirrespective of the character of the construction of these parts.

The gearingherein disclosed mploys the general principles of the gearing shown de-' scribed and claimed in 'my copending application filed December 30, 1924, Serial No. 7 58,940, which is essentially a gearing connection between driving and driven members .including an eccentrically mounted, internal-external gear' member having a geared connection with the driving member and having also a gear connection with the -also includes means for connecting the driv- .ing shaft to the eccentric bearing whereby all of the gear members are tied together so as to rotate as. a unit when direct drive is desired. It also includes retarding the rotation of the internal-external gear while permitting it a revolving movement tosey v v indicating the various parts by numerals or cure a low reverse speed or a very low fortions. the present invention, I propose to use any method for preventing or retarding the rotating movement of the composite gear, that shown in the drawings however, employin the use of a series of cranks pivoted to t e composite gear' at one end and to anidler member at the other and olfset a distance'corresponding to the amount of eccentricity of the bearing for the gearing.

This prior application- I. g, I I I Application filed December 30, 1924;. Serial No. 758,942.

Thus when the member which cranksare secured is held against rotation the composite gear ,isstill mechanism wherebythe cost of manufactur ingthe gearing may be decreased. For example the earlier application provided means for partially synchronizingthe speed the driving shaft and that of the eccen- "tric by a centrifug'ally operated clutchpreviousto positively coupling the two members together .to secure di'rectdrive. In the presentcase, the means employed for lock mg all thezmembers together is simplified and generally consists of clutching the eccentric bearing to the composite gear member and thus preventing relative rotation and consequently any reduction of. speed. Provision may be made for partially equalizing or synchroni'zin the speed of the rela- PATENT OFFICE."

allowed to revolve with .tiveLy moving mem or before positively clutching them together if desired, similar to thatof the former embodiment.

Other features will-become apparent in .the following description which relates to the accompanying drawings wherein I have shown. the preferred embodiment of my invention. The essential characteristics will be summarized in the claims.

Tn the drawings Fig. 1 is a substantially axial longitudinal section through my transmission; Fig. 2 is a transverse section at right angles thereto as indicated by the lines 22 on Fig. 1; Fig. 3 is a similar section as indicated by the lines 3-3 on Fig. 1; Fig.

4 is a fragmentary section of part of the mechanism similar to Fig. 1 and showing'a difierent relation of some of the elements; Fig. ,5 a transverse section "taken along the l1ne 5-5 of Fig. 1. f

Referring in" detail to the drawings and letters,- 1 indicates the driving shaft having a pinion P r'igid therewith and meshing with an internal gear of larger diameter indicated at P The internal gearforms part of an composite gear member 3 having an eccentric bearing member 4, The member 3 has also external gear teeth a-t'P. which mesh with internal gear teeth P on the driven member or propeller shaft 5. Suit able bearings are provided for these memhere. in a casing indicated generally at 7 comprising a rearward portion 8, a bearing supporting web or partition 9 and forward sections 10 and 11 adapted to be secured to,

the engine or bell housing of the usual construction. The ropeller or driven member is shown as carried by roller bearings 12 in the rearward end of the casing while the rearend of the driving shaft as well as the eccentric" bearing'andcomposite gear may be also supported indirectly by these bear- 3 ings throu h roller bearings 13 carried by The driving end by rollthe propel e11 gear member. shaft is supported at the other ers 14 carried by the support 9.

One of .the features of this invention is i the arrangement whereby I provide a ri "(1 which it will be seen that the rearward end ofth'e eccentric bearing member has a tubu-.

I lar portion 20, and a lune'shaped body porsimilar body tion 21 shown'best in Fig. 2 which lies between the pinion teeth and the 'gearP diametrically opposite the tangent point of the two gears. The forward end of the eccen tric istubular as at 23 and has a somewhat portion projecting through from i the opposite direction and lying against. the lune shaped portion 21 as at 24.

One or more pins or bolts may be provided as at 25 for securely holding thetwo parts of the eccentric member together. Thus to assemble the eccentric. onto the shaft, the

. two sleeve-like portions may be slid toward each other from opposite ends of the shaft.

The bearing as shown is provided with roller bearings 27 at the rearward end. For the first speed reduction the eccen tric is-held' rigid with the casing, and tori. effect this. a member 30 having a braking surface 31 and being provided with a 00 operating brake band 32 operable from a shaft 33 extending into the casing, is made rigid: with the eccentric members as by means of a ke 'or spline 34, when the brake is applied an the eccentric held the reduction is-the compound reduction between the gears P and.P and P and P.

The composite gear member as heretofore mentioned is provided with cranks 40 having their pivots offset a distance correspondingto the degree of eccentricity of the bearing for the composite gear. The cranks may be arranged as shown in Fig. 2 about the I exterior of the composite gear and supported at one end in gear 41 extending therefrom and at the other by amember 42 ri 'd with abrake member '43 shown as free y journaled on a rearward extension 30 of the member 30. I have shown a cooperating brake member 60 arranged to be operated by a rockshaft-Gl for holding the member 43 against rotation. The composite gear is consequently held against rotation by reason of the cranks permitting only a revolving movement of the gear. The result of' this' arrangement is that when the brake is oper ated the driven memberis rotated at a slow reverse speed as will be hereinafter more fully explained. The mechanism for efiectingthe Synchronous rotation of. the driving and driven shafts 1' and5 consists of means for connecting-the braking member 43'to the member 30. I preferably provide clutch teeth 44 rigid with .the member 43 and adapted to esh with the complementary teeth of a clutch collar 46. The collar maybe operated in the usual manner by abifurcated arm 47 carried by a shaft 48 and jour} naled'in the casing in bearings 49 as shown .in Fig. 5. By this means, Lam enabled to hold the braking member 43 rigid with the braking member 30 andhence also rigid with the eccentric bearing. Thus when direarwardly from its normal position illustrated in Fig. 4 to its clutching position as shown in Fig. 1, locking the eccentric bear-" infg and the composite gear, together and 8 so rect drive is desired, the collar 46 is thrown I tually preventing the rotating movementof the composite gear and consequently reduction of speed.

When the reverse is desired, the clutch collar 46 assumes its normal position and the brake 60 is applied to hold the member 43 relatively stationary, preventing rotating movement of the compositegear but ermitting it to revolve about the eccentric aring which is now spinning backwardly to per mit the revolving movement of the gear.

The eccentric rotates in a reverse direction to that of the rotation of the driving shaft carrying with it the composite -gear,'and the gear P imparts to P a reverse movement. v i In connection withmy previously filed application above referred to the various gearing' One that case cori s eeds of the members has been described in dgtail with assumed ratios of of the embodiments (Fig. 2) o responds substantially with that shown in the drawin of the present application. The

speed relatlons given below are therefore the same for this case. V

When the eccentric bearing is held as above descrlbed and-wlth an assumed engine shaft speed of 600 R. P. M. the forward speed is found to .be 272.3. The reverse speed accomplished as above explained by the creeping backward movement of the composite gear while allowing the eccentric to turn freely backwardly, is found to be 186.5. These speed combinations are very still further reduced .gine shaft, all Within the general casing for 'to, secure direct drive.

' claim p'osite gear member rotate as a unit for sepractical from the standpoint of wear on ing and said internal-external gear member the'mechanism as well asfor the usual traflic rotate as a unit to effect a change of speed of requirements. y the driven member. a

It is to be understood that the particular 3 In a gearing of the class described, a gear relations shown are merely illustrative, driving member, a pinion carried thereby, an and for an illustration of different forms internal-externalgear in mesh with said pinembodying the same principles as herein set ion, an eccentric bearing therefor, a driven out, I refer to 'my .c'opending application member having a geared connection with said above mentioned. in ernal-external gear, means for holding the The unbalance of the eccentric is compcncomposite gear member against rotation of the member 30 within the eccentric holdcentric bearing, a braking member rigid with ing braking members 31. The location. of the eccentric bearing for holding the bearing this counterweight may of course be changed against rotation relative to the driving memsated by a counterweight 50 shown as part while permitting it to revolve about the ec- I i within the spirit of my invention to attain her, and means comprislng a clutch collar a better dynamic. bal c f he rota ing in splined-relation to the braking member parts. In this embodiment I have shown a capable of being shifted to clutch th B kfly wheel 51 keyed to the driving shaft 1 ing member to said holding means whereby and adapted to be connected with the en all of the members may be rotated as a unit my gearing. This and other details of con- 4. In a gearing in combination a driving struction above set out I do not recognize as member having a p1n10n,-a' composite gearessentlal and I do not WlSll to .be precluded member in mesh'Rvith said'pinion, an eccenfrom my right to manufacture and prevent 'tric bearing for said gear member capable of others from manufacturing any mere meindependent and synchronous rotation relachanical. equivalent of the combinationheretive to the driving member, a driven member in set forth; 4 3 having a geared connection with said com- Having thus described .my ,invention, I posite gear, means for holdingsaid coma posite gear against rotation while permit- 1. In a transmission gearing in combination ting it to revolve upon the eccentric bearing a driving member, a gear rigid therewith, a when the bearing is free to rotate independrotatable and revoluble composite gear mem-. ently and means forrigidly connecting said ber having a plurality of sets of. teeth rigid holding means to said eccenfric bearing when with each other, said gear member being in ,it is desired to rotate all of the members as offset axial relation to vthe driving member a unit for directdrive.

and having one set of teeth in mesh with the 5. In a gearing, in combination, a casing. gear thereof, a driven member and a gear a driving member having a pinion located rigid therewith meshing with another of said therein a composite gear member in mesh sets, means for retarding the rotating movewith said pinion, an eccentric bearing for ment of the gear member but permitting a resaid gear member capable of rotation relavol vi ng movement thereof 'for imparting a tive to the casing and independently of the low speed to the driven member, a bearing for driving member or of beingiheld rigid with said gear member independent of the dr1v1ng the casing, a driven member having a geared member, adapted to rotate idly when said reconnection with said composite gear, means tarding means is operating and means for :for holding said composite gear against rotaconnecting said bearing to said retarding tion while permitting it to revolve abont the means whereby said bearing and said comeccentric bearing when the bearing is independently rotating to impart a reduced speed curing another speed of the driven member. to the driving member, means for holding 2. In a transmission gearing in 'combinathe eccentric rigid with the casing for antion a driving member, a rotatable and revoother reduced speed, and means for rigidly luble internal-external gear in offset axial connecting said first named holding means relation thereto and havlng a geared connec-- to said eccentric bearing when it is desired tionotherewith, a driven member having a to rotate all of the members as a unit for geared connection with said internal-exterdirect drive. r nal gear, means for retarding-the rotating 6. In a gearing, in combinatlon, a driving movement of the internal-external gear but shaft, .a pinion rigidly, carried thereby, a permitting the revolving movement thereof hollow eccentric bearing member surroundfor imparting a low speed toythe driven mg said shaft and comprlslng separate member,,'a bearing for said internal-external parts extending along said shaft, one forgear mounted to rotate relative to the driv- Wardly and the other-rearwardly from the ing member and adapted to so rotate when pinion, means extendlng parallel to the said retarding means is operating, andshaft and positioned adjacent the radial ends a clutching meansfor connecting said bearing of a portion of the pinion teeth for rigidly 65 to said retarding means whereby saidbearclamping the sald parts together, a com- 30 with said composite gear.

'7. In a gearing, in combination, a driving shaft, a pinion rigidly carried thereby, a

ing, said shaft and comprising separate parts, one extending along said shaftfor- -wardly and the other rearwardly from the plnion, said two parts being secured together in overlapping relation substantially oppoion teeth and adjacent thereto, an internalexternal gear in mesh with said pinion supsitethe radial ends of a portion of .the pinor-ted by both parts of said bearing memer, the internal teeth thereof meshing with the pinion, and a driven member having in- ;ternal teeth in mesh with the external teeth of the gear;

' 8. In a'gearing,'in combination, a driving shaft, a'p nion carried thereby, a rotatable eccentric bearing member formed of a plurality of sections located exteriorly of said shaft, and extending along said shaft at both sides of said pinion, anti-friction bearings carried by-said eccentric member positioned at either side of said pinion, a hollow composite gear member supported by said bearing having a plurality of sets of'teeth rigid with each other, one set being of larger pitchdiameter than-the inion and in mesh with and surrounding t e pinion, means including-connected overlapping tongues extendingi from respective sections of the eccentric an located between the teeth of the pinion and the teeth-of said larger gear for maintaining. the sections in rigid relation, a driven member having a eared connection with saidinternal-external gear, means for retarding the rotation of the internal-external gear while permitting the bearing member to-r'otate for securing a given spee relation between the shafts, andtmeans for I locking all the said elements together for securing direct drive between the shafts.

9. In a gearing, in combination, a drive shaft, a pinion formed on said shaft, a rotatable eccentric bearing member formed of a plurality of tubular sections surrounding said shaft, each section being adapted to'be assembled over its respective end of the shaft, clamping means adjacent the pinion and extending around the same for securing the sections together, a composite ear member supported by said bearing an having a plurality of sets of teeth rigid with each other, one set being in mesh with the pinion and embracing both the pinion and clamping means, rolling bearings interposed between hollow eccentric bearing member surround the gear and each section, rolling bearings 10 for supporting the eccentric bearing member, one for each of the sectlons, and a driven member having a gear in mesh with the other gear of the composite" gear member.

' 10. In a gearing, a shaft, a-pinion carried thereby, a composite gear member'having a ,plurality of sets of teeth rigid with each other, one set, being in mesh with the pinion,

an eccentric bearing for the ear, another.

member having a, driving connection with the eccentric bearing and a cooperating clutch member drivingly connected with the controlling means, and means for bringing the, clutch members together to couple thebearing to said controlling means whereby independent rotation of the gears and bearing is prevented for effecting direct drive between the shafts; 11. In a gearing, in combination, a shaft having a pinion, a composite gear member having a plurality of gears rigid with each other, one being in mesh with the pinion, an eccentric bearing for said gear member ca pable of independent and synchronous rotation relative to the shaft, another shaft, and a gear drivingly connected thereto, in mesh with a second gear of said composite gear member,"'means for holding the composite gear member against rotation while permitting, it to revolve upon the eccentric bearing;

whereby the bearing, gears and shafts may be constrained to rotate as a unit. 1

, In testimony whereof, I hereuntoaifix my signature. s

CHARLES E. F. AHLM. 

